Header design for Supercharged applications?
#1
Header design for Supercharged applications?
Well, I know there is a wide variety of headers available, but I wonder if the R&D was done based on NA approach and not thinking ahead about a supercharged app...
For example: On mu buddys integra, we made decent power with the jackson SC and a DC Sports header. He swapped to a Kamikaze header and made immediate power (8-9 hp consistent in 4 pulls).
So, this is on my mind. I wonder if the stillen, alpha, nismo, dc sports etc are all designed to make power with NA, but not with SC. I wonder if the crawordz is any different?
Is there a SC specific header I am not aware of. I am new to the 'G' world. I bought mine last week and spent a lot of time surfing.
What are the SC'd veterans running for header. I assume anything is better than stock, but there must be one that responds better to SC, I am guessing!
Thanks in advance! I hope to learn a lot from all you knowledgable people!
For example: On mu buddys integra, we made decent power with the jackson SC and a DC Sports header. He swapped to a Kamikaze header and made immediate power (8-9 hp consistent in 4 pulls).
So, this is on my mind. I wonder if the stillen, alpha, nismo, dc sports etc are all designed to make power with NA, but not with SC. I wonder if the crawordz is any different?
Is there a SC specific header I am not aware of. I am new to the 'G' world. I bought mine last week and spent a lot of time surfing.
What are the SC'd veterans running for header. I assume anything is better than stock, but there must be one that responds better to SC, I am guessing!
Thanks in advance! I hope to learn a lot from all you knowledgable people!
#2
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With how hard it is to put on headers on this car . I dont think any one has swapped headers just to find the best flowing with a SC . Im running BRM headers...a Nismo knock off . They must flow good enough as I was only able to get less than 7psi out of the stock Vortech Kit . Crawford makes some nice headers . They are longer pipes [ 25 inch ] most are 23 inch , and Crawfords bolt up right to the stock exhaust
#3
Without a doubt any longtube headers such as Xerd. No cats + longer runners + equal length = power. You have a 2003.5 so your car won't throw codes without cats so you are good there. If you are in CA then it's a no-no. I live in FL so don't tell the EPA but I run test pipes. This should give nice gains on a supercharged car.
Last edited by djniknala; 08-21-2005 at 10:28 PM.
#4
Your hinus (a "king" joke)...
I got the following e-mail this morning from BJ at 350EVO...
By next Saturday I should have a ton of dynos to show. G8tor20 is getting a Vortech S/C installed on his STOCK 2005 G35C-5AT and I'm getting the Vortech installed on my modded 2004.5 G35C-6MT. I have the Crawford headers, Plenum and Cats so we'll see how much hp/tq I'm making and hopefully Jason will have a boost gague so we can compare psi numbers from car to car...
We'll also be doing a second set of dyno runs on another dyno that is ~500 miles away from where we're installing the S/C on Saturday. This will hopefully be useful to see if the runs are repeatable.
![Big Grin](https://g35driver.com/forums/images/smilies/biggrin.gif)
I got the following e-mail this morning from BJ at 350EVO...
Todd,
We cannot release dyno numbers as they are done by our engine builder and they will not release them.
I can tell you that from the ones we tested..Nismo, Xerd, our first prototype set.....Crawford made better torque.
We are currently developing headers that we think will be a better race design...but as of right now ..Crawfords are the best of the shelf headers available for the 350Z and G35.
Cheers
BJ
Now this was for NA vehicles, but I'd like to believe that if a header flows better NA then it would flow better with FI.We cannot release dyno numbers as they are done by our engine builder and they will not release them.
I can tell you that from the ones we tested..Nismo, Xerd, our first prototype set.....Crawford made better torque.
We are currently developing headers that we think will be a better race design...but as of right now ..Crawfords are the best of the shelf headers available for the 350Z and G35.
Cheers
BJ
By next Saturday I should have a ton of dynos to show. G8tor20 is getting a Vortech S/C installed on his STOCK 2005 G35C-5AT and I'm getting the Vortech installed on my modded 2004.5 G35C-6MT. I have the Crawford headers, Plenum and Cats so we'll see how much hp/tq I'm making and hopefully Jason will have a boost gague so we can compare psi numbers from car to car...
We'll also be doing a second set of dyno runs on another dyno that is ~500 miles away from where we're installing the S/C on Saturday. This will hopefully be useful to see if the runs are repeatable.
#6
That is a leap of faith. You are going from a car that has no positive pressure on the intake side to one that does. It changes the exhaust scavenging characteristics of the engine so it's not that cut and dry. That's why engine builders will ask you what you are doing with the motor(SC, turbo, NA) before they do things such as valve job or porting. You can't go wrong with the Crawfords but as a rule longtube headers work better on SC cars.
Originally Posted by neffster
Now this was for NA vehicles, but I'd like to believe that if a header flows better NA then it would flow better with FI.
#7
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#9
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Originally Posted by Randys_G
with a SC, you DO NOT want that much free flowing pressure...you'll lose boost pressure from lack of back pressure...you'll lose the venturi effect that SC'ers are all about...TT, yes, SC, no.
Last edited by booger; 08-22-2005 at 09:07 PM.
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Originally Posted by booger
I would like to see some thing writen by an expert on the subject of back preasure being good for a SC . As you may already know I went through it .Crawford plenum , Headers , open RT cats , stillen dual . At 7psi I made 350whp on a Mustand dyno....ADD 12% for you Dynojet guys..392 WHP on a AT5 . Put on Crawford cats ....made 9.5psi and lost power . Retuned A/F....reduced timing retard a little and made 350WHP .....392 WHP...Dynojet numbers . So Please tell me how back preaasure is good ???? The higher numbers you got may be because you have a MT6 or Im just not adding enough to my numbers
#14
Just because the amount of boost goes down doesn't mean that the effective cfm of the engine is going down(IE: able to make less power). On my turbocharged engine I was making the same boost on the stock motor 9psi(at 78% duty cycle) than I was on my built motor with ported head and cams. The difference was to get to the same AF I was maxing out the duty cycle of the same injectors with the same fuel pressure and boost. This is because the motor was breathing better and making more power. The same thing is happening when you take off cats and put on test pipes. I bet that you could add some timing back in when you go to the test pipes and this will yield more power over the more restrictive exhaust and I higher manifold boost pressure. Do you guys tune with a way to watch the knock sensor?
Originally Posted by booger
I miss stated the boost I had....on the 3.12 pulley I made 8psi...put on the Crawford cats and gain 1.5psi .....lost power...gained it back by tuning